Movable dam



' no Model.)

B. F. THOMAS. I MOVABLE DAM.

Patente d'D-eg. 29, 1896.

UNITED s STATES PATENT QFFICE.

BENJAMIN F. THOMAS, OF LOUISA, KENTUCKY.

MOVABLE DAM.

SPECIFICATION forming part of Letters Patent 1\To. 574,229, dated December 29, 1896.

Application filed Juno 9, 1896. Serial No. 594,877. (No model.)

To all whom it may concern:

Be it known that I, BENJAMIN F. THoMAs, of Louisa, county of Lawrence, and State of Kentucky, have invented a new and useful Improvement in Movable Dams, of which the following is a specification.

The object of myinvention is to form a dam or barrier across a stream or waterway which can be raised and lowered at will, as the conditions may require. I accomplish this result by means of a series of A-shaped trestles placed side by side upon a foundation suitably constructed in the river-bed and properly hinged to journal-boxes made fast to said foundation. When standing, these trestles, or, rather, the upstream posts of these trestles, form the barrier which dams the water up and holds it back, and when down they lie one within another on the foundation and offer no obstruction to navigation and are themselves protected by a sill standing on the foundation whose crest is as high as the depth of the'trestles when lying down. The raising and lowering of these trestles are accomplished by means of a continuous chain connecting with each trestle, hauled in by suitable machinery established upon the wall of the pass to be dammed or other accessible point in the manner described farther on. The upstream post of the trestle has a decided inclination downstream,while the downstream leg inclines upstream, so that at the top or head the two posts touch each other, while at bottom they are far apart. They are suitably assembled and bound together at head, and at bottom they are formed into eyes or holes for connection with the j ournalboxes. A walkway is placed on top slightly above proposed pool-level. This is so constructed that one half of it will fold over the top of the trestle when desired, the top of the trestle itself forming the other half. The

tops of successive trestles are connected with short lengths of chain for assistance in lowering, as will be described, and also to have some means at hand for raising them should the maneuvering-chain become disconnected from the trestles or otherwise fail. The upstream posts closely touch the sill to prevent leakage. v

In the accompanying drawings, in which suitable construction.

similar letters of reference indicate like parts, Figure 1 is a downstream elevation showing two trestles upright and others in the act of being raised or lowered. Fig. 2 is a side view of a trestlestanding, showing the water dammed up on its upstream side to nearly the level of the opening r, through which it flows when it rises above its normal height. Fig. 3 is a plan view of two whole trestles and parts of others lying on the foundation, the floor F folded back on top. Fig. at is an enlarged section of the heads of two trestles, one standing and the other in the act of being raised or lowered, showing also the ratchet and pawl. Fig. 5 is a top or plan View of the chain or pocket wheel and ratchet, and Fig. 6 is a part sectional elevation of the same thing. I

In the drawings, A is the downstream and B the upstream legs of trestle.

O is the pocket-wheel or chainwheel on which the maneuvering-chain J travels.

D is the ratchet; E, the pawl; F, the walkway, which is hinged to the trestle-head at p and when in position for use rests on a projection g, which is a part of F and which in turn rests against the trestle-frame. When not in use, F is folded back on the trestle-top, as shown in Figs. 3 and 4.

G is the downstream journal-box; H, the upstream journal-box; I, the sill closing the spaces upstream of the trestles; J, the maneuvering-chain, which remains normally engaged with the series of wheels 0 by reason of its own weight, its links fitting in corresponding recesses in the wheels, as shown in Figs. 5 and 6.

K isa chain connecting adjacent trestles; L, one wall of the pass in which the dam is 'built; M M, pins connecting bottoms of tres-.

tles with journal-boxes; N, the foundation or floor on which the dam is built.

Some parts of the construction of the trestle-head which may vary with the ideas of constructors, but which are not claimed as original, are, for the sake of clearness, omitted from the drawings.

1 The maneuvers of my dam consist in raising and lowering the same by machinery of To raise it, attach the maneuvering-chain J to a suitably-com structed winch, properly located, and windy in the chain. This will bring up the first trestle and also start several others, the number depending upon the lengths of the con necting-chains between successive trestles. \Vhen the first trestle becomes vertical and its head strikes the pass-wall L,the outwardlyprojecting arm e of the pawl E will also strike the said wall and be forced inward, and the pawl thereby tilted on its pivot, as shown in righthand portion of Fig. 4, so that its nose will be thrown up orlifted out of the ratchet D and will remain out as long as the pressure continues. This will permit the chain-wheel C, to which the chain being wound in is held, to turn, thus releasing the wheel, and in consequence the trestle in which it is fastened, so that the chain may pass on toward the winch. As the maneuverin g-chain is held to the chainwheel of each trestle to be raised at intervals equal to the lengths of connecting-chain K between these trestles, it will only be necessary to wind in that amount of chain in order to bring each successive trestle to its upright position. As soon as the trestle being raised strikes the last one put in position the pawl is released from the ratchetand the chain passes on toward the winch, allowing another trestle to come to an upright position. Thus the whole number constituting the dam will be raised, and the half of the floor F which lies folded on top of each trestle will remain to be revolved to its proper place, when the dam will. be complete. To perform the opposite maneuver, that of lowering the trestles, it will first be necessary to slacken the chain J on the winch by unwinding a portion of it from the latter, and then to fold the floor or walkway sections F upon top of each trestle, then pull or push the head of the last trestle raised away from the one adjacent to it, and said trestle falls into a recess in the wall (not shown) that is opposite L. 13y such movement of the first trestle the next one is also drawn down and separated from the one next to it through the medium of the connecting-chain K, and as soon as this separation takes place the pawl E falls into the ratchet D, and thus stops the wheel 0 from turning, and fastens the chain J upon it. Then by continuing to unwind the chain J the next to the last trestle (as well as the last trestle) will be lowered until it stretches the chain K between it and its neighbor, when this trestle will in turn commence lowering. Thus the whole number will be let down to the floor in the bed of the river, their chains resting upon and under their heads.

The space 0' in the trestles is left open to allow surplus water to pass and prevent the foot-bridge F from overflowing. Its floor reaches from the upper to the lower sides of the trestles and forms a connection between the two posts of each trestle.

I am aware that a continuous chain has been used f or raisin g trestles forming part of a movable dam, but not in connection with a chain-wheel or other device working automatically.

\Vith this description of my invention,wl1at I claim is- 1. A movable dam composed of a series of frames, or trestles, which are pivoted side by side, their pivots being arranged substantially in the direction of the flow of water, so that when said frames stand vertical they are parallel to the general direction of such flow, and when folded they move transversely, or at right angle, to the same, as shown and described.

2. A movable dam composed of a series of frames pivoted at the base, side by side and adapted, when placed in horizontal or reclining position, to lie one within another, as shown and described.

3. A movable dam composed of a series of triangular trestles, each formed of two ri gid1yconnected beams arranged at an angle to each other and pivoted at their widely-separated bases, which are alined in the direction direct] y opposing the pressure of water in the dam,a folding foot-bridge consisting of boards or flat sections hinged to the truncated tops of the respective trestles, and means for supporting the foot-bridge when thrown out and adjusted for use, as shown and described.

L. In a movable dam, the combination with the pivoted trestles having flat tops, of footbridge sections which are hinged to said tops, and adapted to fold outward as specified, and pieces q attached to such sections on the outer side, whereby they are adapted to support the same by contact with the side of the trestlcs, as shown and described.

5. A movable dam composed of a series of triangular frames or trestles which are pivoted at their bases side by side, and whose faces, when erect, abut and form a practically continuous front or water-breast, as shown and described.

6. A movable dam composed of a series of frames which are pivoted and adapted to swing and fold laterally, means for loosely connecting them, and means for raising and automatically adjusting and holding them in close contact, substantially as shown and described.

'7. In a movable dam, the combination with a series of pivoted and laterally-swinging frames, of a series of chain-wheels journalcd in their upper portions, means for locking them against rotation, and consisting of a pawl, a chain resting free on said wheels and extending from one to another, substantially as shown and described, whereby when the chain is tightened or slackened, the wheels are held immovable, but may be released to allow the frames to swingdownward, as shown and described.

8. In a movable dam, the combination with a series of pivoted frames adapted to be folded or laid. down in the direction of the dam,chainrollers journaled in the heads of such frames, cal position, thus tilting the pawls and unlocka chain running on said wheels, for raising ing the chain-whee1s,a,s shown and described. and lowering the trestles, pawls pivoted adjacently and their free ends projecting later- BEN, AMIN 5 ally, a fixed abutment against which and the Vitnesses:

adjacent trestles such free ends of the pawls JOHN M. S. \VATT,

strike when the trestles are raised to a verti- I D. A. WATT. 

